Checked 2026-11-10. Independent clinical review has not been completed. WADAFUK is independent of WADA and does not provide medical advice or an individual anti-doping determination.
Prohibited at all times
4-Hydroxytestosterone is covered by S1.1 of the effective 2026 WADA List and is prohibited in and out of competition. S1.1 applies to exogenous administration; its coverage is not limited to the named examples and includes relevant esters. [3]
S1.1; 2026 List, printed pages 5–6 · 2026 rules apply from 1 January 2026. Any 2027 material below concerns future rules from 1 January 2027; it is not current clearance.
Human research
A phase I trial studied topical CR1447, identified as 4-hydroxytestosterone, in 14 patients with advanced breast cancer. It assessed tolerability and uptake and reported limited early disease-stabilization observations. [1]
- Small uncontrolled oncology study. It does not establish clinical effectiveness, current approval or safety for performance use. 4-hydroxytestosterone is not the same molecule as 4-hydroxyandrostenedione.
List year
The 2026 List is the effective edition on this review date. The checked 2027 S1 text showed no change, but the 2027 edition does not take effect until 1 January 2027. [3] [4] [2]
- Consult the official edition and responsible anti-doping organization for consequential decisions. This reference does not provide medical advice, a TUE decision, product certification or individual clearance.
What remains uncertain
- This is a targeted source check, not a systematic review or independent clinical/regulatory sign-off. Uncited draft claims remain unpublished.
- Chemical registry identifiers, every alias and jurisdiction-specific product availability have not been exhaustively reconciled.
Check the sources.
These are concise editorial paraphrases of selected sources, not a systematic review or a reproduction of source tables. Access depth is shown for each reference; an abstract-only check cannot resolve details found only in a full paper.
- Phase I trial of the androgen receptor modulator CR1447 in breast cancer patients. ↗Accessed 2026-11-10 · indexed original abstract read via Europe PMC MED record; full article not reviewed
Abstract; PMID 28814476
- 2027 Prohibited List resource page ↗Accessed 2026-11-10 · relevant primary-source text read · FUTURE 2027 SOURCE
Resource description and effective date
- WADA 2026 Prohibited List ↗Accessed 2026-11-10 · relevant primary-source text read
Introduction and S1, printed pages 3, 5–6
- WADA 2027 Prohibited List, currently linked English file ↗Accessed 2026-11-10 · relevant primary-source text read · FUTURE 2027 SOURCE
Cover and S1, printed pages 1, 5–6
Check the current official WADA List and the relevant anti-doping authority for your sport, product, route and circumstances. Do not stop or change necessary treatment based on this page. Ask a qualified clinician about health decisions. Missing evidence does not establish safety.